PROJECT SUMMARY There are very few controlled studies on the oral health of older HIV-infected individuals, especially postmenopausal women. This is of particular concern in the U.S, where more than half of HIV-infected individuals are over age 50. Our group has previously demonstrated that bone loss at the spine and hip is greater and fracture rates higher in HIV-infected than uninfected women after menopause. Our preliminary data also show that HIV-infected women over age 50 had greater alveolar bone loss and a trend for fewer teeth compared to age-matched uninfected controls. However, the separate and/or combined contribution of HIV infection and estrogen deficiency to oral immune activation and the observed alveolar bone loss is uncertain. Therefore, the goal of this study is to determine the extent and progression of periodontal disease in HIV-infected pre- and postmenopausal women on antiretroviral therapy and to investigate the contribution of periodontal immune activation to its pathogenesis. We hypothesize that HIV-infection is associated with increased oral immune activation, and loss of the beneficial immune-modulatory effects of estrogen results in an increased inflammatory response to periodontal pathogens, and greater alveolar bone loss after menopause. To determine the impact of HIV infection and menopause on periodontal health, will perform a cross-sectional study of 240 HIV-infected and uninfected pre- and post-menopausal women. We hypothesize that HIV-infected postmenopausal women will have evidence of worsened clinical periodontal parameters, higher GCF inflammatory biomarkers, greater alveolar bone loss and fewer teeth than uninfected post-menopausal women, and both HIV-infected and uninfected pre-menopausal women. In the general population, men appear to have a higher prevalence of periodontal disease and greater severity of periodontitis women at all ages. There are very few studies published on sex-differences in periodontal disease among HIV-infected individuals. With this administrative supplement, we will be able to enroll 120 HIV-infected and uninfected men with similar ages as the women enrolled in the parent R01, so that we can compare the prevalence and severity of periodontal disease between older HIV- infected and uninfected women and HIV-infected and uninfected men and explore the role of inflammation and sex hormones on periodontal disease in the context of HIV infection.